Cutting die and process

ABSTRACT

The cutting die is made from strip steel and comprises a die blade having a cutting edge formed with sawteeth and chamfered surfaces extending along said cutting edge on opposite sides of said blade. To cut through a material which comprises a fabric having first filament portions extending in a predetermined direction and second filament portions extending transversely to said predetermined direction, said material is cut into at a plurality of discrete points which are spaced apart on an intended line of cut extending in said predetermined direction and said first filament portions which are disposed adjacent to said line of cut are pushed laterally away from said line of cut. At the same time, the cutting into said material is continued along said line of cut until said second filament portions extending across said line of cut have been severed.

United States Patent [19,

Spengler et al.

[ Aug. 13, 1974 CUTTING DIE AND PROCESS Inventors: Ernst MaximilianSpengler,

l-leusenstamm; Rolf Karl Stursberg, l-laan, both of Germany.

Martin Miller Gesellschaft m.b.H., Vienna, Austria Filed: Jan. 10, 1973Appl. No.: 322,458

Related US. Application Data Division of Ser. No. 216,464, Jan. 10,1972.

Assignee:

Foreign Application Priority Data Jan. 14, 1971 Germany .Q 2101543 Jan.14, 1971 Germany 7101204 References Cited UNlTED STATES PATENTS 6/1914Lewis 83/697 1,288,038 12/1918 Krook 83/485 X 2,576,492 11/1951 Vogel30/355 X 3,593,611 7/1971 Sagehorn 83/620 X Primary Examiner-J. M.Meister Attorney, Agent, or Firm-Toren and McGeady [57] ABSTRACT Thecutting die is made from strip steel and comprises a die blade having acutting edge formed with sawteeth and chamfered surfaces extending alongsaid cutting edge on opposite sides of said blade. To cut through amaterial which comprises a fabric having first filament portionsextending in a predetermined direction and second filament portionsextending transversely to said predetermined direction, said material iscut into at a plurality of discrete points which are spaced apart on anintended line of cut extending in said predetermined direction and saidfirst filament portions which are disposed adjacent to said line of outare pushed laterally away from said line of cut. At the same time, thecutting into said material is continued along said line of cut untilsaid second filament portions extending across said line of cut havebeen severed.

1 Claim, 5 Drawing Figures PAIENIEB nus 3:924

-SHEET 1 BF 2 FIG. 2

FIG.!

CUTTING DIE AND PROCESS This is a division of application Ser. No.216,464, filed Jan. 10, I972.

This invention relates to a cutting die which is made from strip steeland consists of a blade provided with chamfered surfaces extending alongthe cutting edge of the die.

Such cutting dies made from strip steel are used mainly for cutting orsevering textile fabrics, artificial leather reinforced with wovenfabric and plastics material, and have a straight cutting edge. Inaddition to these cutting dies made from strip steel, cutting dies areknown in which the cutting edges are zig-zag-shaped in order to fix theedges of textiles. Because the line of cut formed by these dies islonger than that obtained with cutting dies made from strip steel andhaving a straight cutting edge, a higher cutting pressure is required. Acommon aspect of both types of cutting dies made from strip steelresides in that each cutting operation results in the severing also of aplurality of threads which are parallel to the actual line of cut.

It is an object of the invention to provide a cutting die which is madefrom strip steel and which does not sever threads which extend in thewoven fabric parallel to the cutting edge so that only the warp threadsor only the filling threads are severed, and which can be operated undera lower cutting pressure than the known cutting dies made from stripsteel.

This object is accomplished according to the invention in that thecutting edge is formed with sawteeth. As a result, the cutting toolfirst enters the material to be cut at discrete points and those threadsof the woven fabric which extend substantially parallel to the line ofout are pushed aside before those threads of the woven fabric aresevered which extend transversely to the line of cut. Those threadswhich have been pushed aside are not severed so that the resulting cutedges are neater than those obtained before. Besides, the cuttingpressure required to operate the die having the novel cutting edge ismuch lower because the cutting edge enters the woven fabric to besevered at a multiplicity of almost pointlike cutting portions ratherthan along a continuous line extending on one level.

For this reason it is a special feature of the invention that the teethhave pointed ends and each tooth has a pyramid-shaped portion adjacentto its pointed end.

In a development of the invention, each tooth has adjacent to itspointed end a portion in the form of a quadrangular pyramid, two of theedges which extend toward the pointed end of the pyramid-shaped toothportion constitute cutting edge portions which lie in a plane whichextends in the longitudinal direction of the die blade and include anacute angle with each other, those edges which extend transversely tothe cutting edge portions terminate at the chamfered surfaces of the dieblade and include an angle which is larger than the angle included bythe two chamfered surfaces, and the tooth side faces which extend fromthe pointed ends of adjacent teeth terminate and adjoin adjacent to thechamfered surfaces farther from the pointed ends than the edges of saidpyramid-shaped portion.

It is also a feature of the invention that each tooth has adjacent toits pointed end a portion in the form of a triangular pyramid.

The invention will now be described more fully with reference to thedrawing, which shows two illustrative embodiments.

FIG. 1 is a side elevation of a cutting die according to the invention.This cutting die is made from strip steel, and each of its teeth hasadjacent to its pointed end a portion in the form of a quadrangularpyramid.

FIG. 2 is a vertical sectional view taken on line IIII in FIG. 1.

FIG. 3 is an elevation showing another embodiment in which each toothhas-adjacent to its pointed end a portion in the form of a triangularpyramid.

FIG. 4 is another elevation showing the embodiment of FIG. 3 and FIG. 5is a sectional view taken on line VV in FIG. 4.

The cutting die 1 which is shown in FIG. 1 is made from strip steel andcomprises a die blade 2 having chamfered surfaces 4 and 5 and a cuttingedge 3 formed with sawteeth. Teeth 8 are provided adjacent to thechamfered surfaces 4 and 5 and each of said teeth has a pointed end 9and adjacent to said pointed end 9 a tooth portion 10 in the form of aquadrangular pyramid. Edge portions 11 and 12 extending from the pointedends 9 serve as cutting edge portions and are aligned with the pointedends 9 to provide a straight line of cut, which extends in thelongitudinal direction of the die blade.

The other two edges 13 and 14 of the tooth portion 10 having the form ofa quadrangular pyramid extend transversely to the cutting edge portionsfrom the pointed ends 9 to the chamfered surfaces 4 and 5 and terminateat the latter. As is particularly apparent from FIG. 2, the angle whichis included by the two edges 13 and 14 is larger than the angle which isincluded by the chamfered surfaces 4 and 5.

The teeth 8 have side faces 15 and 16, and the chamfered surfaces4 and 5on the opposite sides of the tooth blade 2 also form tooth side faces.The side faces 15 and 16 extend farther away from the pointed ends 9than the cutting edge portions 11 and 12 and the edges 13 and 14 whichare transverse to the edges 11 and 12.

FIGS. 3 to 5 show another embodiment, in which the cutting edge 3a isprovided with teeth 8a which have pointed ends 9a and adjacent to saidpointed ends have tooth portions 10a in the form of a triangularpyramid. A side face 17 of the pyramid-shaped tooth portion 10a directlyadjoins a chamfered surface 4a of the die blade 2a. The other two sidefaces 18 and 19 of each tooth have a common edge 20 and terminate on oneside at the side face 17 which is transverse to the longitudinaldirection of the die blade 2a, and on the other side at a chamferedsurface 5a on that side of the die blade 2a which is opposite to thesurface 4a. Edges 21 and 22 defined jointly by the side faces 17 and 18and 19 extend from the pointed ends 9a at an angle to the longitudinaldirection of the die blade 2a and serve as cutting edge portions.

FIGS. 1 and 2 show the cutting die 1 which is made from strip steel andmaterial 25 to be cut, which material rests on a base 26, which iscarried by a support 27. When severing the material 25 to be cut, theteeth 8 of the cutting die 1 made from strip steel penetrate to someextent into the base 26, which may consist of hard rubber, syntheticplastic materials or similar materials. Specifically, the base mayconsist of a material which is softer than the material to be cutbecause the cutting die 1 according to the invention, which is made fromstrip steel, exerts only a relatively slight cutting pressure in avertical direction on the material to be cut and on the base. Owing tothe horizontally directed component of pressure, satisfactory cuttingoperations may be performed also on plastics materials, such asstyropor, hard synthetic foams, etc. This has not always been possiblebefore owing to the difficulties involved in the initial penetration ofthe cutting die into the material to be cut.

We claim:

1.A process of cutting a material which comprises a fabric having firstfilament portions extending in a predetermined direction and secondfilament portions extending transversely to the predetermined directionof the first filament portions, cutting the material in a line extendingin the predetermined direction of the first filament portions by firstinserting a continuous cutting member into the material and making aplurality of spaced punctiformed openings aligned in the predetermineddirection of the first filament portions, continuing the passage of thecutting member through the punctiform openings and directing the firstfilaments adjacent the cutting member laterally away from the line ofthe punctiform openings and gradually increasing the width of thepunctiform openings on both sides in the predetermined direction of thefirst filament portions, first directing the first filament portionslaterally along oppositely directed first planar surfaces each formingan acute angle with a plane extending perpendicularly to the materialalong the cutting line, continuing the lateral displacement of the firstfilaments along oppositely directed second planar surfaces each forminga continuation of one of the first planar surfaces and also forming anacute angle with the plane extending perpendicularly to the materialalong the cutting line and with the second planar surfaces forming asmaller acute angle with the prependicular plane than the first planarsurfaces, and continuing the passage of the second planar surfacesthrough the material and widening the individual openings until adjacentopenings join to form one continuous opening and thereby cutting thematerial without severing the first filaments. l

1. A process of cutting a material which comprises a fabric having firstfilament portions extending in a predetermined direction and secondfilament portions extending transversely to the predetermined directionof the first filament portions, cutting the material in a line extendingin the predetermined direction of the first filament portions by firstinserting a continuous cutting member into the material and making aplurality of spaced punctiformed openings aligned in the predetermineddirection of the first filament portions, continuing the passage of thecutting member through the punctiform openings and directing the firstfilaments adjacent the cutting member laterally away from the line ofthe punctiform openings and gradually increasing the width of thepunctiform openings on both sides in the predetermined direction of thefirst filament portions, first directing the first filament portionslaterally along oppositely directed first planar surfaces each formingan acute angle with a plane extending perpendicularly to the materialalong the cutting line, continuing the lateral displacement of the firstfilaments along oppositely directed second planar surfaces each forminga continuation of one of the first planar surfaces and also forming anacute angle with the plane extending perpendicularly to the materialalong the cutting line and with the second planar surfaces forming asmaller acute angle with the prependicular plane than the first planarsurfaces, and continuing the passage of the second planar surfacesthrough the material and widening the individual openings until adjacentopenings join to form one continuous opening and thereby cutting thematerial without severing the first filaments.